A fully tested shot may not be ready until year's end, WHO says
MONDAY, July 13 (HealthDay News) -- A fully tested swine flu vaccine may not be available until the end of the year, a vaccine expert at the World Health Organization said Monday.
But countries could use emergency measures to get the vaccines out faster if they decide they are needed, Marie-Paule Kieny, director of WHO's Initiative for Vaccine Research, said during a news conference in London, the Associated Press reported.
The problem: The swine flu viruses being used to develop a vaccine are only producing about half as much "yield" to make vaccines as regular flu viruses. So the WHO has asked its network of laboratories to produce a new set of viruses as soon as possible. Before countries can start any large-scale swine flu vaccination campaigns, the vaccines need to be vetted by regulatory authorities for safety issues, the AP reported.
The good news is that the H1N1 swine flu virus is still producing relatively mild cases of infection and most patients recover quickly.
Still, U.S. health officials are very aware that a swine flu vaccination campaign in 1976 was abruptly stopped after hundreds of people reported developing Guillain-Barre syndrome, a paralyzing disorder.
Also Monday, U.S. researchers reported that the H1N1 swine flu virus causes more lung damage than a seasonal flu strain -- at least in some animals. But the virus is still susceptible to antiviral drugs such as Tamiflu.
Reporting in this week's issue of the journal Nature, University of Wisconsin-Madison scientiss Yoshihiro Kawaoka and colleagues took virus samples from patients infected with the H1N1 swine flu and examined their impact on different types of animals. In mice, ferrets and monkeys, infection with the new H1N1 swine flu virus triggered more severe lung disease than a seasonal H1N1 strain.
That may explain why
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